The invention described herein relates generally to optical switching method and apparatus, and more particularly to an optical switching device wherein light from a first or a second glass fiber may be selectively transmitted into a third glass fiber.
It is a common practice in the present optical field to switch light between bare glass fibers by reflecting it from a rotatable concave mirror. Such an optical switch is taught by Wagner in U.S. Pat. No. 4,261,638 issued Apr. 14, 1981.
It is also known in the present optical field to achieve light switching between glass fibers by either passing or not passing the light through a transparent dielectric plate of uniform refractive index. Such switches are taught by Aoyama in U.S. Pat. No. 4,239,331 issued Dec. 16, 1980, and by Minowa et al in U.S. Pat. No. 4,322,126 issued Mar. 30, 1982.
Nevertheless, there remains a need for an optical switch that is economical, dependable and easy to work with, and efficient with respect to light loss.